🌟IMPORTANT DEFINTIONS IN ORTHODONTICS
🔸ADAPTIVE SWALLOWING PATTERN: A swallowing pattern that exists when a normal lip-to-lip anterior oral seal cannot be achieved.
🔸ANCHORAGE: The resistance to unwanted three-dimensional forces generated in reaction to the active components of an appliance.
🔸ANGLE CLASSIFICATION: A classification of malocclusion introduced by Edward Angle based on the anteroposterior relationship of the first permanent molars.
🔸ANGULATION: The mesiodistal angulation of the long axis of a tooth in relationship to a line drawn perpendicular to the occlusal plane (compared with inclination).
🔸ANKYLOSIS: An abnormal fusion between two bones or between a tooth and bone.
🔸ANODONTIA: The developmental absence of all primary and secondary teeth.
🔸ANTERIOR OPEN BITE: No vertical overlap exists between the maxillary and mandibular incisors when the molars are occluded.
🔸ANTERIOR ORAL SEAL: A seal produced between the lips, the lower lip and palate or the tongue and lips to prevent expulsion of a bolus during mastication.
🔸ARCH FORM: The shape of the mandibular or maxillary arch.
🔸ARCH WIRE: A wire engaged into orthodontic brackets to provide the active forces for tooth movement and/or a stable platform for bodily tooth movement.
🔸AUTOROTATION: Rotation of the mandible around the condylar axis following vertical maxillary repositioning.
🔸BALANCING EXTRACTION: Extraction of a contralateral tooth during the mixed dentition to minimise a shift of the dental centreline (compare with compensating extraction).
🔸BILATERAL SAGITTAL SPLIT OSTEOTOMY (BSSO): A surgical mandibular procedure, where the ramus is split parallel to the sagittal plane, commonly used to advance, setback and rotate the mandible.
🔸BIMAXILLARY: Relating to both upper and lower dentoalveolar segments.
🔸BIMAXILLARY PROTRUSION: A term used to describe protrusion of the maxilla and mandible in relationship to the cranial base.
🔸BIMAXILLARY RETRUSION: A term used to describe retrusion of the maxilla and mandible in relationship to the cranial base.
🔸BOLTON (tooth size) DISCREPANCY: A mismatch between the sum of mesiodistal widths of the maxillary and mandibular dentition making it difficult to achieve an ideal occlusal fit.
🔸BUCCAL SEGMENT: The canines, premolars and molars.
🔸CAMOUFLAGE (orthodontic): Occlusal compensation of mild/ moderate skeletal discrepancies by orthodontic tooth movement.
🔸CENTRIC OCCLUSION: The position of maximum intercuspation.
🔸CENTRIC RELATION: The relationship between the mandible and maxilla with the condyles in an unrestrained retruded position within the glenoid fossae.
🔸COMPENSATING EXTRACTION: Extraction of an opposing tooth during the mixed dentition to prevent its over-eruption (compared to balancing extraction).
🔸COMPETENT LIPS: An anterior lip seal can be achieved with minimal muscular activity with the mandible in the rest position.
🔸COMPLETE OVERBITE: The lower incisors occlude with the upper incisors or palatal mucosa when the teeth are in occlusion.
🔸COUPLE: A pair of equal and opposite parallel forces applied to a body.
🔸CROSSBITE: An abnormal relationship between occluding teeth in a buccolingual and/or labiolingual direction.
🔸CURVE OF SPEE: A convex curve, when viewed in the sagittal plane, produced by the curvature of the cusps and incisal edges of the mandibular teeth. The depth of the curve positively correlates with the depth of the overbite.
🔸DECOMPENSATION: The removal of adaptive occlusal changes in the dentition which mask the severity of a skeletal discrepancy. It is undertaken prior to orthognathic surgery.
🔸DENTO-ALVEOLAR ADAPTATION: The dynamic process of occlusal adaptation, produced by favourable soft tissues, which masks the severity of an underlying skeletal discrepancy in the anteroposterior, vertical or transverse dimension.
🔸DENTO-ALVEOLAR COMPENSATION: A static snapshot of occlusal adaptation, produced by favourable soft tissues, which masks the severity of a skeletal discrepancy in the anteroposterior, vertical or transverse dimension.
🔸DEVIATION (mandibular): A sagittal movement of the mandible during closure from a habit posture into centric occlusion.
🔸DIAGNOSTIC (Kesling)SETUP: A diagnostic laboratory procedure where the teeth are sectioned from a duplicate model and realigned into their desired position to study the occlusal outcome of a proposed treatment plan.
🔸DIASTEMA: A naturally occurring space between teeth.
🔸DILACERATION: The presence of an abnormal bend or curve in the root or crown of a tooth commonly as a result of dental trauma.
🔸DISPLACEMENT(mandibular): A sagittal and/or lateral movement of the mandible on closing from centric relation into centric occlusion as a result of an occlusal interference.
🔸DISTRACTION OSTEOGENESIS: A surgical technique for lengthening bones, and their associated soft tissue envelope, involving corticotomy followed by gradual separation (distraction) of the bone segments (1 mm/day) and osseous infill.